Electronic musical instrument switch means



NOV- 3 1964 H. M. THOMAS ETAL 3,155,760

ELECTRONIC MUSICAL INSTRUMENT SWITCH NEANs 6 Sheets-Sheet 1 Filed June 26, 1962 INVENTORS mijne www# p. w/,M 4 m 5 N Q w aw 5 f5 m H5 Ww w 5 m E m Z K w m 5 NOV- 3, 1964 H. M. THOMAS ETAL 3,155,760

ELECTRONIC MUSICAL INSTRUMENT SWITCH MEANS Filed June 26, 1962 6 Sheets-SheetI 2 Nov. 3, 1964 H. M. THOMAS ErAl. 3,155,760

l ELECTRONIC MUSICAL INSTRUMENT SWITCH MEANS Filed June 26, 1962 6 Sheets-Sheet 3 @s @55' Mm NGV 3 1964 H. M. THoMAs ETAL 3,155,760

ELECTRONIC .MUSICAL INSTRUMENT SWITCH MEANS Filed June 26, 1962 6 Sheets-Sheet 4 YN' l .S .kg

INVENTORS Nov. 3, 1964 H. M. THOMAS ETAL 3,155,760

ELECTRONIC MUSICAL INSTRUMENT SWITCH MEANS Filed June 26, 1962 6 Sheets-Sheet 5 @f Mw@ m Wwwgg Nov. 3, 1964 H. M. THoMAs ETAL 3,155,760

ELECTRONIC MUSICAL INSTRUMENT swITCH MEANS Filed June 26, 1962 6 Sheets-Sheet 6 god/111:MMMMMMM1M 7M. mm M 'Il o .a Umted States Patent C) ce 393537275@ Patented Nov.. 3, '11h64 FiG. i3 is another fragmentary perspective view showdtdti ing r et another embodiment of the invention; and ELJLCTRNEQ MUSKCAL iNSltUPfiENT Fit?. i4 is a fragmentary side view of a further modi- SWilitCH MEANS Howard M. ihornas and Hm'aid E., W. Bode, North 'iiona- Wanda, NY., and .Fehn assignors to The Wurlitzer Company, Chicago, iii., a corporation of @hie Filed .inne 26, i962, Ser. No. 205,377 i2 Claims. (Cl. 84m-Mii) This invention relates to the electronic production of music, and particularly with improved pedal switching means for an electronic organ.

As is well known, it is common for electronic organs to have one or two manuals or keyboards, plus a pedal board or clavier. Commonly, the pedals are connected to borrow notes from the generators controlled by the manuals, the frequency of such notes often being divided to produce the desired lower tones. Generaily speaking, only one pedal tone is played at .a time. In tact, it is extremely undesirable to play more than one adjacent pedal tone at a time, since the notes are sucientiy low in frequency that a very bad beat is produced between adjacent, or even nearby notes controlled by the pedal board. Various switching arrangements have heretofore been developed in an eiort to insure such one-note-at-atime playing. However, such systems have often proved troublesome due to the necessity of maintaining critical tolerances or sequences of switch operation.

Accordingly, it is an object of this invention to provide an improved pedal switching arrangement for playing one pedal note at a time in an electronic piano.

It is a further object of this invnetion to provide a pedal clavier in an electronic piano positively insuring that the switch to one note will be open with or before the closing of the switch for another note.

Yet another object of this invention is to provide an improved pedal arrangement for electronic organs wherein the necessary sustain is provided for each pedal note, but wherein each note may be rapidly repeated, it desired.

Other and further objects and advantages f the present invention will be apparent from the following description when taken in connection with the accompanying drawings wherein;

FIG. i is a perspective View of an electronic organ incorporating a pedal strutcure constructed in accordance with the principles of the present nvention;

FIG. 2 is a block and schematic diagram of the various parts of the organ;

FIG. 3 is a fragmentary perspective View on a greatly enlarged scale of a portion of the pedai clavier;

FIG. 4 is a perspective view on a greatly enlarged scale of a switch and switch operator as mounted on each pedal and forming a part of the present invention;

FiG. 5 is a perspective View of a portion of the device of FiG. 4 and. speciiically comprising a mounting bracket;

Pif. 6 is a perspective view of the switch actuator as shown in FIG. 4 and cooperating with the bracket of HG. 5;

FIG. 7 is a side view of a portion of a pedal and the associated switch and switch operator structtne;

FG. 8 is a view similar to FIG. 7, showing the parts in a different position or" operation;

FIG. 9 is a view similar to FIG. 7 and showing the parts in yet another' position of operation;

Fifi. 10 is another View similar to FIG. 7 and show* ing the parts in yet a diterent position of operation;

FG. ll is a fragmentary perspective view of a rnodied pedal clavier;

FIG. l2 is a side View of a portion of a pedal and of associated switch structure similar to that shown in FiG. 11, but modified somewhat therefrom;

Ei. Brand, Pacoima, Gaiif.,

cation of the invention.

Referring now in greater particularity to the drawings, and nrst l, there will be seen an electronic organ, designated generally by the numeral it?, and constructed in accordance with the principles of this invention. The organ Zd includes a cabinet ZZ. it is provided with a pair of manuals or keyboards 2d, and with a pedal clavier Suitable stop tablets 28 are provided controlling which banks of tones are to play, and also to control relative intensities of the notes of the different manuals, and to control vibrato effects. The electronic organ is also provided with a swell pedal 3@ tor controlling the instantaneous overali volume of the organ. Loudspeakers are provided behind grills 32 in the organ cabinet.

ittention now should be devoted to schematic diagram of FIG. 2, illustrating the electronic aspects of the organ. lThe organ is provided with a plurality of tone generators of any known or suitable type. Preferably, the organ is of the subtractive type in which complex tones are generated, each of which is replete with harmonics which are selectively filtered to produce the desiredtone quality. Further, for purposes of illustration, the tone generators may be electronic tube or transistor oscillators, or they may be wind driven vibratile reeds with capacitive or inductive type pickups.

The tone generators are connected to respective key switches These in turn are connected to the filters and stops ior controlling which tones are to be delivered to the arnpiiiier di?, and inaliy to the loudspeaker d?. for converting the amplified electric oscillations into audible organ tones.

The tone generators 3.?, serve also to provide the pedal notes. Specifically, the lowest thirteen half-tones 'are respectively connected to isolating resistors i4 and to pedal switches do. These pedal switches are connected to a common co-iiector riti leading to an amplifier 5d.

The amp .ner is connected to a iirst divider 52 for ividing the frequency oi thc tones from the generators to provide tones one octave lower. The irst divider is connected to the tiiters and stops 3S, and it arso is connected to a second divider for producing tones yet another octave lower. The second divider also is connecteu to the iilters and stops Both or" the dividers S2 and 5d are normally inoperative to produce an output, by virtue of a lack of B+ or plate potential applied trereto.

Accordingly, as is indicated on Fi-G. 2, B+ is pro- 'ided through a normally open switch 56. Tais switch is arranged so as to be ciosed mechanically at the time any of the pedals 2o is depressed to close one of the switches ed, as wiii be brought out hereinafter. The B+ sonoiy continues from the switch 5o through a resistor 53, and through respective resistors and d?. to the iirst and second dividers 52 and 54. Provision is made for sustaining the pedal tones comprising a shunting capacitor ed on the B+ supply line, a shunting resistor ed and a sustaining switch o3, and another shunting resistor 7i? and a short sustaining switch '72.

As will be more apparent in connection with the physicai structure hereinafter, whenever a pedal Z6 is depressed, the switch 56 is closed, and the respective switch ed is closed. Thus, a stable tone from the tone generators 34- is supplied through the amplifier Sti to the iirst and second dividers S2 and 54. Which of these two dividers wiil play is determined by the setting of the stops and the co-action with filters as determined by the stop tablets Zd. Suhtantially concurrently with the closing of one of these switches 46, the switch Sd the block or essere() closes to provide the B+ potential to the dividers, whereby to `cause them to operate. When the pedal 26 is released, the corresponding switch remains closed, whereby to provide the stable tone to the dividers. However, the switch opens, and the output of the dividers continues ier a short period, determined by the `setting of the switches 6d and if the same pedal is again depressed, the corresponding switch remains closed, and the switch Se is re-closed, again to provide B+ potential to the dividers 52 and lf a ditierent pedal is depressed, the switch ed is opened, and the respective switch corresponding to` the newly d pedal is closed. Simultaneously, the switch d is reclosed. Accordingly, a dilierent tone is produced. The structure for opening one switch upon the closing of another switch 46 will be set forth immediately hereinaiter.

Reference now should be had to FIGS. 3-7 for a description of the pedal, switch and switch operating structure. Thus, the pedals 26, which are generally of conventional design, are pivotally mounted by means of dexure springs 76 secured as by rivets to the upper horizontal flange "itl of a sheet metal pan Si), which is suitably secured within the organ cabinet 22.. The iexure springs 76 may also be riveted to the pedals. The pan Sil near the front edge thereof has raised horizontal flanges 32 received within the pedals, both to stabilize the pedals laterally, and to serve as downstops for tre zierlals. A common upstop is provided by the pedals in the form of a rail S4 supported on posts d'6 which upstand from the pan 8h. The rail Se extends across the tops of all of the pedals.

Each pedal 26 has mounted on the top thereof, and near the pivot end, within the organ cabinet, a switch operator designated generally by the numerai Each such operator includes a sheet metal bracket Siti, best seen in FIG. 5. All of the switch operators are of identical construction, and la description of one serves for all. Thus, continuing primarily with FlG. 5, each brachet 9@ .includes a horizontal base ange 92, having near the opposite ends thereof a pair of apertures 94s through which pass screws threaded into the tops of the pedals for mounting the brackets 953. Each base flange 9?; has near the rear or inner end thereof, a thin pad of mate rial of limited resiliency, such as neoprene, such pad being identilied by the numeral 9o, and adjacent pad 9?; of greater height, and much greater compliance. For example the pad 9S may be made of polyurethane. As will be brought out hereinafter, the pad @d serves to decelerate a member while the pad 96 serves as a iinal resilient stop.

A vertical, upstanding frange itl@ is integral with the horizontal base flange 92 along a longitudinal edge thereof, and a Acutout in?, is provided at the junction of the two llanges to facilitate the forming of the bracket 9d. The vertical flange is provided lat its front or outer end with an extending finger idd disposed substantially parallel to the pedal 2d and having an upward extension litio from which an overlying horizontal flange projects back over the base flange 92. The ange lili-l lies on the same side of the vertical iiange liti@ as does the base iiange 92.

Along the top of the vertical dange lldfii, and toward the back or linner end thereof at a lower level than the flange 16S, there is provided a horizontal flange laid. A small pad M2, as of neoprene, is provided beneath the rear portion of this flange. Arearward extension lid of the vertical flange supports a bifurcated h rizontal flange il@ at an intermediate level above the base flange 92. The switch lo is supported on one of the bifurcations il of the ange llo. in the illustrative embodiment, this is the bi urcation adjacent the vertical llange lill?. it additional switch functions arU to bc operated by the pedals, a like switch can be mounted on the other bifurcation. The switch lo simply can comprise a d single movable contact and a single iixed Contact, in line with the schematic showing of PEG. 2. However, as will be brought out presently, in accordance with a modification ci the invention, there may be a single movable contact in combination with a pair of xed contacts.

Somewhat toward the front end of the vertical ilange idd, and generally midway from the top to bottom, there is provided an aperture i2@ for receipt of a pivot pin im having an enlarged head i213 with a felt washer beneath it. This pin is for the pivotal mounting of a switch actuator shortly to be described.

Forwardly of the pin llZ, a 4plastic spring anchor 12S is mounted on the side of the vertical flange by means yof ya screw 13@ passing the spring base or anchor and threaded into the flange itltl. The anchor or base SL23 is provided on its back side with a projection received in an a ture (not shown) in the hangs lili? positively to posi-tion the spring base 12d in co-action with the screw The spring base is provided with a if-shaped channel or trough llSZ for receipt of one laterally extending end 131i (FIG. 7) of a hairpin shaped spring i3d, operating as an overcenter spring, as hereinafter set forth.

A switch actuator i3d is formed of molded plastic and is provided with a peripheral reinforcing flange Mil. The switch actuator is of an elongated nature, and has near its midpoint a hub extending in both directions from the plane of the web from which the llange lid-d extends. T he hub llt?. is provided with a central lbore ldd receiving the pin 22 for mounting the actuator on the bracket 9d.

rl`he actuator 13S is of substantially equal length on opposite sides of the hub i412, and .is provided with a raised heel ldd normally resting on a felt pad it@ on top of the rail A similar pad li@ is provided beneath the rail and engageable with the pedals 2d in` limiting their upward movement. As will be apparent, the felt pads hold noise at a minimum.

Spaced in from the heel M6 toward the pivot as provided by the hub i412 and bore 144i on the pin 122, there is a il-shaped trough 152 receiving the opposite end ilange llSl of the hairpin spring i3d. The hairpin spring acts as an o-vercenter spring with the center points comprising the pivot pin 122, the spring base or trough 132, and the spring base or trough i152. The spring 136 preferably is-made of sheet metal, and may, for example, be of spring steel or phosphor bonds.

At its opposite end, the actuator i3d is provided with transverse projection 15o substantially parallel to the bore ldd, and having a substantially cylindrical bore therethrough opening along an element thereof for reception of the movable arrn of the switch do. The opening provides opposed, substantially knife edges i558. The projection i556 is sufciently long that the movable arms of two switches respectively mounted on the bifurcations of the may be simultaneously operated although only one such switch is shown. A transverse wall (parallel to the web of the actuator ll) divides the projection whereby to insure electrical isolation between two switch arms, and also to provide mechanical strength.

The details of one of the switches lo may be seen in FIG. 7. This switch includes a movable switch arm ist? having an extending end received between the knife edges T158 of the projection Edil. Contact means 2.62 are mounted on opposite faces of the switch arm ist?. The upper of these two contact means engages a complementary contact on a lixed switch arm i643, while a lower is engageable with a Contact on a second fixed switch arm ieri. With the parts in the normal rest position as shown in FIG. 7, the contacts loi of the movable switch arm are spaced from the lower fixed Contact id, and are in engagement with the upper fixed Contact 3179. The contacts i652 and lo@ are all that are represented in FIG. 2, and tor purposes ot FG. 2, the upper switch arm inflaleman and contact 17d could be omitted. Alternatively, as a modification thereof, this upper contact and switch arm may be included, as shown in FIGS. 3-7. For purposes of completing a disclosure relative to this upper switch arm, it will be apparent that this upper switch arm could be grounded, whereby to prevent any spurious signal coming through from the tone generators 3d. Alternatively, the upper and lower fixed switch arms could be arranged in any known or suitable preference circuit to prevent more than one note from playing at any given time, even though more than one switch may be operative. The switch arms are insulated fromone another by conventional insulators, and are secured to the bifurcated lange 116 by screws, which may also hold the insulating members and switch arms together, all in accordance with conventional practice.

Considering now particularly FIGS. 3 and 7, a pair of brackets 172 are respectively mounted on the sheet metal pan il@ on opposite sides of the group of pedals 2d. A pivot rod 174 extends between the brackets 172, overlying the pedals and the switch operators Sd. The pivot rod 174 preferably is pivotally received in suitable busiings in the brackets 172, and forms a mounting means for a bail designated generally by the numeral 176. The bail conveniently is made of extruded aluminum, and includes a cylindrical portion 173 fitting over the pivot rod 174, anda ange or plate 179 integral therewith and eX- tending forwardly above the operator heels 146 and beneath the flanges 1138 of the mounting brackets 9d. The flange or plate 179 of the bail is provided with an integral stiifening rib 18d extending from end to end thereof. A felt strip or pad 182 lies along the upper, outer edge of the bail plate 179 for engagement by the bracket flanges 1% to insure quiet operation. A similar strip or pad 18d of felt may lie beneath the plate adjacent the outer edge thereof, for engagement with the operator heels 146.

The bail is normally pivoted to its upper limit position as illustrated in FIG. 7 by means of a plurality of leaf or blade type springs 186 supported from the liange 7S of the pan d@ and cantilevered out beneath the plate 179 of the bail 176. Besides biasing the bail up to its normal upper limit position, the springs 186 provide a certain amount of support for the bail intermediate to brackets 172, whereby no brackets or other supports are necessary for the bail intermediate the ends thereof.

As shown in FIGS. 3 and 8, the bail is provided with a switch operating arrn or lever 18d having a front flange or foot 19d secured to the bail plate 179 by means such as a screw. The arm 18S extends diagonally up at 192 from the bail plate, and then down at 194i, clearing the cylindrical portion 173 of the bail, and finally out at 1% beneath the switch 5d. A felt or other insulating pad 198, such as of neoprene, is provided on the outer end of the arm for engagement with the block Ztl@ on the end of the movable arm 202 of the switch 5d. The contact on the movable arm 2192 normally is spaced from the contact on the fixed arm Zilli, but is brought into engagement therewith when the bail is pivoted in a clockwise direction. The switch 56 is mounted in a tipped-up position on a bracket 266 Xed to the llange 7S of the pan Sb.

Operation of the foregoing structure will now be set forth, with particular' reference to FIGS. 7 9. Several parts have been omitted from FIGS. 9 and l0 for clarity of illustration, as will be apparent. rl`he parts are shown in their normal or switch olf position in FlG. 7. When the pedal 26 is depressed by the organists foot the bracket 90 is carried down with the pedal. However, the heel 1456 of the corresponding switch actuator 133 is resting on the felt strip 14S on top of the rail dt, and hence cannot lower. Accordingly, the switch operator 138 pivots about its mounting pin 122. to the position shown in FIG. 8, thus lowering the switch armv 169 to bring the lower contact 162 thereon into engagement with the contact lod el on the lower switch arm 16e, at the same time breaking Contact with the upper switch arm.

The flange 168 necessarily lowers with the bracket 90. Since it is engaged by the felt strip 182 on the underside of the bail 17e, the bail is pivoted in a clockwise direction. This causes the left end of the bracket 18d to rise up beneath the movable arm of the switch Se, whereby to close the Switch substantially simultaneously with closure of the switch d6. Thus, a particular pedal organ tone is selected, and the corresponding divider is energized to pass the tone. When the pedal is released, the bail pivots in a counter-clockwise position, since the flange 193 rises with the pedal, whereby to open the switch 55. However, the spring anchors or troughs 13E and 152 have passed a dead center position relative to the pivot pin 124. Accordingly, the hairpin spring 136 prevents the switch actuator 133 from pivoting back to its normal position.

Accordingly, the heel 1% raises up o the rail pad 14B, as seen in FlG. 9. The overcenter position of the switch actuator 138 causes the actuator to hold the arm 165) of the switch do in its lowered, closed position. Thus, the selected tone oscillation continues to be applied to the dividers. However, the B+ to the dividers diminishes once the Switch Se is opened, and the sustaining capacitor starts to discharge into the dividers, or through the sustain resistors. Thus, a normal pedal organ tone is produced with an organ-like decay period. As otherwise would be the case, the oscillations would be cut olf immediately if the overcenter switch actuator did not hold the switch in actuated position.

Subsequently, when another pedal is depressed as shown in the background of HG. ll) at 25', the bracket gd associated therewith is pulled down so that the flange 19t-i thereof presses down on the switch actuator 138 which has its heel 1536 tipped up into the air. The flange 16S thus returns such switch actuator to its normal, switch off position of FIG, 7. The parts are dimensioned so that the previously tipped switch actuator opens its switch te just before the next switch i6 is closed by the switch actuator on the pedal subsequently depressed, as the pedal 26. lt does not make any difference what switch actuator might previously be tipped up in the air, hence any and all of the flanges .idd engage the bail upon depression of a pedal whereby to pivot the bail in a clockwise direction and return any tipped switch actuator to normal, switch olf position.

A modification of the invention is shown in FlG. ll. Many of the parts are similar to those heretofore described, and similar numerals are utilized, with the addition of the sufx rz. The bail 176a is of somewhat different construction than that previously disclosed, comprising a plurality of forwardly extending arms .293 pivotally mounted on a pivot rod 174er, and carrying at their outer end a transverse rod or bight 211?. A substantially Z- shaped bracket upstands from each hey and has a top dange overlying the bight 211i, for pivoting the bail down against the action of a helical spring 212 stretched between a tail 214iI4 on one of the arms Zlib and a spring anchor hole 216 on the bail mounting bracket 172e. The bight 21@ has a leftward projection Z13 arranged to close the switch dna, which is mounted on an upstanding bracket 22d from the pan lilla.

Each switch ida is structurally rather substantially different from the switches 46 previously disclosed. Each such switch den includes a fiberboard 222 secured on the side of a pedal 26a inwardly of the upstop 84a, by any suitable means, such as screws or rivets 22d. Near the upper edge, there is provided a pair of L-shaped metal members 226, conveniently secured to the board by means of eyelets 22S, which also serve las electrical terminals. The bases or transverse members 230 of the L-shaped metal members 226 extend beyond the edge of the corresponding liberboard 222.

A ber member 232, hereinafter referred to as a butterfly, is pivoted (not shown) on each pedal 2da.

Each of the ber butterliies 232 is provided with an upstanding portion 234i carrying a metal or other conductive plate or the like 23e normally engaged by the lower of the two transverse arms 234i. A felt strip 23S underlies all of the butterflies 232 to limit the lower positions thereof.

When any pedal 2da is depressed, it lowers the two transverse bases 234D of the L-shaped members so that both engage the conductive member or plate 23d, which thereby acts as a shorting bar. When the pedal is released by the organists foot, the L-shaped members 225 frictionally pick up the butterfly 232, thereby retaining the shorting bar 236 in electrical engagement across the transverse members 23d. Subsequently, when another pedal is depressed, the bracket flange litlf thereon lowers the bight 2l@ of the bail 27de. This bight engages an upstanding portieri 244i of the previously raised butterfly, which portion extends above the metal plate 23o ,whereby to depress the butterfly, and to open the connection made thereby. As will be obvious, the projection 2l8 of the bight 2l@ closes the switch 56a whenever any pedal is depressed. As in the previous form of the invention, the switch remains closed without the necessity of introducing any extraneous parts into the switch positively to latch it closed.

A modilication of the invention is shown in FIG. l2 which is quite similar to the embodiment of FiG. l1. T he conductive patch or plate 2Mb on the butterfly 232k is somewhat lower than in FIG. l1, and the pivot for the butterfly is indicated at 242. Generally, the parts are similar to those heretofore shown and described, and similar numerals are used with the addition of the suf- X b. The berboard 222!) carries 1a pair of transverse projecting contacts 23W) at a lower elevation for frictional and electrical engagement with the patch 236k. ln addition, there is a projection which may be metallic or otherwise, indicated at 244, extending toward the butterlly from beneath the iberboard 22219. ln other words, the projection 244 lies between the berboard and the pedal Zeb, whereby the projection 24fland the transverse contacts 23611 actually grip the butterfly between them, thereby to enhance the frictional picking up thereof with less chance of malfunctioning due to wear of the parts.

Helical springs 24d extend from openings 24d adjacent the top of the iberboard 222k to terminals 25@ at the top of a terminal board 252 carried by the upstop rail 8411. The springs therefore may be used to make electrical contact to the transverse contacts 2301) from the terminals 254i.

A further embodiment of the invention involving frictional picking up of a butterfly contact is shown in FlG. 13. Many of the parts are similar to those heretofore shown and described, and similar numerals are used with the addition of the sufx c. ln this instance, each switch loc comprises a butterliy 232e pivoted on a transverse rod 242C. The butterfly is provided with a shorting bar 23de having a pair of upstanding arms 25dthereon. Another insulating member 222C is pivotally supported on the rod 242C, the butterily 232C have a slight offset therein to accommodate for this. The front end of the insulating member 222e is received in a slot in an upstanding bracket 256 aixed to the top of the respective pedal 26e. This insulating member 222C carries three contact patches, respectively 253, Zell, and 262. The patch 25S comprises a common contact, and is secured to one of the terminals of the terminal board 252e by one of the springs 245C. lt is always engaged by one of the arms 254. The other arm 254 in the initial position engages the patch 262. When any pedal 26e is lowered, the bracket 256 thereon pulls down the insulating member 222e, and hence lowers the contact or patch 26@ into engagement with the arm 2515i, the same arm 25d immediately therebeforc leaving the patch 262. The patches 252, 2d@ and 2o.?, are individually connected by the springs 2 lc to terminals on the board 25de. When the pedal is released, the arms 254 are frictionally held by the patches 253 and 26d, whereby the butterfly 232e is raised, and the circuit remains closed between the patches 253 and Zoli. As will be appreciated, a backing up member can be provided opposite the arm 25d, similar to the disclosure in FG. l2. Subsequently, when some pedal 26C is depressed, the bail 276C is pulled down by engagement of the respective insulated member 226e thereagainst, whereupon the bight 220e of the bail lowers the previously raised butterlly 232C, thereby to move the rightmost arm 254 into engagement with the respective Contact 262. The switch therefore comprises a single-pole, double-throw switch. Although the common switch operated by the bail is not shown in FIG. i3, and is also omitted from FIGS. l2 and 14, it will be understood that such switch is supplied.

Still another frictional pickup type of switch arrangement is shown in FIG. 14, for example, with printed circuit boards. A wood base member tliid is substituted for the sheet metal pan itil heretofore used, and the bail 17nd pivots about a rod 27M, resting on a felt cushion 264i in a concave groove across a wood block 266.

Each switch 46d comprises a butterlly 2320i having a shorting har 23nd thereon with a pair of upstanding arms 2SAM. As will be appreciated, there could be a backing-up bar or pressure member on the opposite side of the butterily 232d, as disclosed in connection with FIG. 12. Each butterfly 2326i is ixed to a pivot member 268, pivoted about a transverse rod 242m In addition, there is an insulating member 222e having three conductive patchesthereon, respectively numbered 25M, Zetld and 2626i. The parts are shown in FIG. 14 in the tone playing position in which the butterfly 232d shown has been picked up.

A plurality of helical springs 201er! connects the conductive patches respectively to terminals on terminal boards 2520.', Xedly supported by brackets from transverse frame members 27@ and 272. A strip of felt 274 runs along the underside of the frame member 272 and serves as an upstop for the pivoted insulating member 22de.

A spring 276 is provided on each pivoted insulating member 226e, and this spring cooperates with a projection 27S on the respective pivoted member 26S, thereby forming a detent mechanism. Normally, each butterfly 232d is down, and the end of the corresponding spring 276 lies to the left of the corresponding projection 278, as shown in the dnawings. When a pedal 26d is depressed, the bracket i280.' and underlying felt 182e? thereon depresses the corresponding insulating member 226C. This moves the patch 26M into engagement with the corresponding arm 254i, and upon release of the pedal, the member 226e picks up the butterly 232:1', frictionally, and with the aid of the detent 276, 273. Each butterfly is provided with a transverse projection or stud 280, and the bail is of a more or less comb-like configuration, having radial arms or elements 282 respectively engageable with the studs 23?, whereby to lower any raised butterly upon depression of a pedal 26d, and consequent engagement thereof with the bight 0f the bail.

lt will be appreciated that in embodiments of the invention using the friction pickup, it is the resiliency of the Contact engagement that caused the contacts and the shorting bar to remain in engagement. The resiliency of the overcenter springs is obvious. Thus, in all embodiments of the invention, resiliency is of importance in maintaining the contacts in engagement. Stated another way, the contacts are impositively held in engagement.

ln the ensuing claims, the word digital is used to cover pedals or keys of an electronic organ or other electronic musical instrument.

The speciiic examples of the invention as herein shown and described are for illustrative purposes only. Various changes no doubt will occur to those skilled in the art, and will be understood as forming a part of the present invention insofar as they fall within the spirit and scope of the appended claims.

The invention is claimed as follows:

l. An electronic musical instrument comprising means for providing electric oscillations corresponding to a plurality of different tones, an amplifier for amplifying said oscillations, electro-acoustic transducing means, connected to said amplifier for converting the amplified oscillations into audible musical tones, a plurality of manually operable digitals for said instrument, and a plurality of switches respectively operated by said digitals and respectively interconnected with said oscillation providing means and said amplifier for rendernig said tones respectivel audible, each of said switches comprising at least two contacts, and mechanical means for bringing said two contacts into electrical engagement, said mechanical means remaining in contact engaging position indefinitely, and common means operable by any of a plurality of digitals and operative upon any of said mechanical means in contact engaging position to move said contacts out of electrical engagement upon manipulation of any of said digitals.

2. An electronic musical instrument comprising means for providing electric oscillations corresponding to a plurality of different tones, an amplifier for amplifying said oscillations, electro-acoustic transducing means connected to said amplifier for converting the amplified oscillations into audible musical tones, a plurality of manually operable digitals for said instrument, a plurality of switches respectively operable by said digitals, and respectively interconnected with said oscillation providing means and said amplifier for rendering said tones respectively audible, each of said switches comprising at least two contacts and mechanical means for bringing said contacts into electrical engagement, resilient means for thereafter holding said mechanical means in contact engaging position, and common means operable by any other plurality of digitals, and operative upon any of said mechanical means in contact engaging position, to move said two contacts out of electrical engagement upon manipulation of any of said digitals.

3. An electronic musical instrument as set forth in claim 2, wherein the resilient means comprises overcenter spring means.

4. An electronic musical instrument as set forth in claim 2, wherein the resilient means comprises resilient, frictionally engageable electric contact means.

5. An electronic musical instrument comprising means for generating electric oscillations corresponding to a plurality of different tones, amplifier means for amplifying said oscillations, and electro-acoustic transducing means connected to said amplifier means for converting the amplified oscillations into audible musical tones, electronic divider means for providing electric oscillations of a lower frequency and connected to said amplifier means, a plurality of pedals operable by the feet of a musician, and a plurality of switches respectively operable by said pedals and respectively interconnecting said oscillation generators to said amplifier means for rendering said tones respectively audible at lower frequencies, each of said switches comprising at least two contacts and mechanical means for bringing said two contacts into electrical engagement, said mechanical means remaining in Contact engaging position indefinitely, common means operable by any of a plurality of pedals, and operative upon any of said mechanical means in contact engaging position to move said two contacts out of electrical engagement upon operation of said pedals by the feet of said musician, said divider means normally being inoperative, a source of potential for rendering said divider means operative, and a common switch operated by said common means to connect said potential to said divider means to render the latter operative.

6. An electronic musical instrument comprising means for providing electrical oscillations corresponding to a l@ plurality of different tones, an amplifier for amplifying said oscillations, electro-acoustic transducing means connected to said amplifier for converting the amplified oscillations into audible musical tones, a plurality of manually operable digitals for said instrument, a plurality of switches respectively operated by said digitals and respectively interconnected with said oscillation providing means and said amplifier for renderng said tones respectively audible, each of said switches comprising at least two contacts and mechanical means for bringing said two contacts into electrical engagement, said mechanical means remaining in contact engaging position indefinitely,

' a pivotally mounted bail pivotally operable by any of a plurality of digitals and operable upon any of said mechanical means in contact engaging position to move said two contacts out of electric engagement upon manipulation of any of said digitals, and a cantilever spring engageable with said bail intermediate its ends for supporting said bail intermediate its ends and for resiliently biasing said bail to a retracted position.

7. An electronic musical instrument comprising means for providing electrical oscillations corresponding to a plurality of different tones, an amplifier for amplifying said oscillations, electro-acoustic transducing means connected to said amplifier for converting the amplified oscillations into audible musical tones, a plurality of manually operable digitals for said instrument, a plurality of switches respectively operated by said digitals, and respectively interconnected with said oscillation providing means and said amplifier for rendering said tones respectively audible, each of said switches comprising at least two contacts and means for bringing said contacts into electric engagement, said contacts thereafter being resiliently held in engagement, and common means operable by any of a plurality of digitals and operatively disposed to move any two electrically engaged contacts out of electrical engagement upon manipulation of any of said digitals.

8. An electronic musical instrument comprising means for providing electric oscillations corresponding to a plurality of different tones, an amplifier for amplifying said oscillations, electro-acoustic transducing means connected to said amplifier for converting the amplified oscillations into audible musical tones, a plurality of manually operable digitals for said instrument, a plurality of switches respectively disposed adjacent said digitals, and respectively interconnected with said oscillation providing means and said amplifier for rendering said tones respectively audible, each of said switches comprising at least a fixed contact and a movable contact which are normally out of engagement, an overcenter switch mechanism carried by each of said digitals, and operatively connected to the movable switch contact of the corresponding switch, said overcenter mechanism being movable with each respective digital, fixed means engageable by a portion of said overcenter mechanism to effect overcentering therof, and concurrent movement of said movable contact into engagment with said fixed contact, said contacts remaining in engagement indefinitely due to the overcentering of said mechanism, and common means operable by any of a plurality of digitals and engageable with said overcentered mechanisms upon manual operation to return any overcentered mechanism with the associated switch contacts in engagement to initial position with said contacts out of engagement.

9. An electronic musical instrument as set forth in claim 8 wherein the overcenter mechanism associated with each digital comprises a member pivoted on its digital intermediate the ends of said member, one end of said member being operatively interconnected with the corresponding movable switch contact and the other end being engageable with the fixed means and subsequently engageable by said common means to effect overcentering in either direction.

snaar/ee 10. An electronic musical instrument comprising means for providing electric oscillations corresponding to a plu-` rality of diierent tones, an amplier for amplifying said oscillations, electro-acoustic transducing means connected to said amplifier for converting the amplied oscillations into audible musical tones, a plurality of manually operable digitals for said instrument, a plurality of switches respectively operable by said digitals and respectively interconnected With said oscillation providing means and said amplier for rendering said tones respectively audible, each of said switches comprising movable switch Contact means operably connected to a respective digital and second movable switch contact means positioned adjacent a respective digital and engaged by the rst mentioned switch contact means upon movement of the respective digital to complete a circuit, said first and second movable switch contact means subsequently remaining frictionally in engagement, and common means operable by any other plurality of digitals and operative upon said switch means l?? in engagement to move said switch contact means out of engagement upon manipulation of any of said digitals.

1l. An electronic musical instrument as set forth in claim 10 wherein the second movable switch contact means comprises conductive means on an insulating, pivotally mounted butterfly.

12. An electronic musical instrument as set forth in claim l() wherein one of the movable switch Contact means comprises a pair of spaced apart switch contacts fixed relative to one another, and the other movable switch contact means comprises a shorting bar engageablc with said spaced apart contacts.

eterences Cited in the file of this patent` UNITED STATES PATENTS 2,480,132 Hammond et al. Aug. 30, 1949 2,493,358 Gswald Jan. 3, 1950 2,577,753 Hanert Dec. 11, 1951 2,626,325 Hammond et al ian. 20, 1953 2,922,329 Hanert Jan. 26, 1960 

5. AN ELECTRONIC MUSICAL INSTRUMENT COMPRISING MEANS FOR GENERATING ELECTRIC OSCILLATIONS CORRESPONDING TO A PLURALITY OF DIFFERENT TONES, AMPLIFIER MEANS FOR AMPLIFYING SAID OSCILLATIONS, AND ELECTRO-ACOUSTIC TRANSDUCING MEANS CONNECTED TO SAID AMPLIFIER MEANS FOR CONVERTING THE AMPLIFIED OSCILLATIONS INTO AUDIBLE MUSICAL TONES, ELECTRONIC DIVIDER MEANS FOR PROVIDING ELECTRIC OSCILLATIONS OF A LOWER FREQUENCY AND CONNECTED TO SAID AMPLIFIER MEANS, A PLURALITY OF PEDALS OPERABLE BY THE FEET OF A MUSICIAN, AND A PLURALITY OF SWITCHES RESPECTIVELY OPERABLE BY SAID PEDALS AND RESPECTIVELY INTERCONNECTING SAID OSCILLATION GENERATORS TO SAID AMPLIFIER MEANS FOR RENDERING SAID TONES RESPECTIVELY AUDIBLE AT LOWER FREQUENCIES, EACH OF SAID SWITCHES COMPRISING AT LEAST TWO CONTACTS AND MECHANICAL MEANS FOR BRINGING SAID TWO CONTACTS INTO ELECTRICAL EN- 